`#lv`
`2x-1/4=6/18 . 9/2`
`=>2x-1/4=3/2`
`=>2x=3/2+1/4`
`=>2x=6/4+1/4`
`=>2x=7/4`
`=>x=7/4:2`
`=>x=7/4 . 1/2`
`=>x=7/8`
__
`x-4/5=6/20 . (-7/3)`
`=>x-4/5=(6.(-7))/(20.3)`
`=>x-4/5=-7/10`
`=>x=-7/10+4/5`
`=>x=-7/10+8/10`
`=>x=1/10`
__
`x+5/6=16/42 . (-8/56)`
`=>x+5/6=8/21 . (-1/7)`
`=>x+5/6=-8/147`
`=>x=-8/147-5/6`
`=>x=-16/294-245/294`
`=>x=-261/294`
`=>x=-36/49`
__
`(1/3-2x).2/5=-8/25`
`=>1/3-2x=-8/25:2/5`
`=>1/3-2x=-8/25 . 5/2`
`=>1/3-2x=-4/5`
`=>2x=1/3-(-4/5)`
`=>2x=1/3+4/5`
`=>2x=5/15+12/15`
`=>2x=17/15`
`=>x=17/15:2`
`=>x=17/15 . 1/2`
`=>x=17/30`
\(1)\) \(2x-\dfrac{1}{4}=\dfrac{6}{18}.\dfrac{9}{2}\)
\(2x-\dfrac{1}{4}=\dfrac{3}{2}\)
\(2x=\dfrac{3}{2}+\dfrac{1}{4}\)
\(2x=\dfrac{6}{4}+\dfrac{1}{4}\)
\(2x=\dfrac{7}{4}\)
\(x=\dfrac{7}{8}\)
\(2)\) \(x-\dfrac{4}{5}=\dfrac{6}{20}.\dfrac{-7}{3}\)
\(x-\dfrac{4}{5}=\dfrac{-7}{10}\)
\(x=\dfrac{-7}{10}+\dfrac{4}{5}\)
\(x=\dfrac{-7}{10}+\dfrac{8}{10}\)
\(x=\dfrac{1}{10}\)
\(3)\) \(x+\dfrac{5}{6}=\dfrac{16}{42}.\dfrac{-8}{56}\)
\(x+\dfrac{5}{6}=\dfrac{8}{21}.\dfrac{-1}{7}\)
\(x+\dfrac{5}{6}=\dfrac{-8}{147}\)
\(x=\dfrac{-8}{147}-\dfrac{5}{6}\)
\(x=\dfrac{-87}{98}\)
\(4)\) \(\left(\dfrac{1}{3}-2x\right).\dfrac{2}{5}=\dfrac{-8}{25}\)
\(\dfrac{1}{3}-2x=\dfrac{-8}{25}:\dfrac{2}{5}\)
\(\dfrac{1}{3}-2x=\dfrac{-8}{25}\times\dfrac{5}{2}\)
\(\dfrac{1}{3}-2x=\dfrac{-4}{5}\)
\(2x=\dfrac{1}{3}-\dfrac{-4}{5}\)
\(2x=\dfrac{5}{15}-\dfrac{-12}{15}\)
\(2x=\dfrac{17}{15}\)
\(x=\dfrac{17}{30}\)
